/**
 * Copyright (c) 2010 by Kevin Bierhoff.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *    1. Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *    3. Neither the names of the authors nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.googlecode.syper.javasyp.checker;

/**
 * Common interface for {@link ObjectType}s and {@link ArrayType}s.
 * @author kevin
 * @since Mar 30, 2010
 */
public interface RefType {

	/**
	 * Returns the permission for the reference itself (as opposed to array dims)
	 * @return the permission for the reference itself, never {@code null}
	 * @see #getElemDims()
	 */
	public PermKind getPerm();

	/**
	 * {@code false} if {@link #isReleased()} even though the source annotations
	 * allow both {@code borrowed} and {@code released} to be {@code true}.
	 * This will be {@code true} for return types of methods and constructors
	 * with parameters that are {@link #isReleased()}.
	 * @return
	 */
	public boolean isBorrowed();

	/**
	 * {@code false} if {@link #isBorrowed()} even though the source annotations
	 * allow both {@code borrowed} and {@code released} to be {@code true}.
	 * @return
	 */
	public boolean isReleased();

	/**
	 * Neither {@link #isBorrowed()} nor {@link #isReleased()}
	 * @return
	 */
	public boolean isConsumed();

	/**
	 * Compares this with the given type.
	 * @param other
	 * @return <code>true</code> if this type is at least as strong as {@code other}
	 * <code>false</code> if strictly weaker or the two types are incomparable.
	 */
	public boolean isStrongerThan(RefType other);

	/**
	 * Returns the strongest type weaker than this and the given type.
	 * This is a symmetric operation as long as {@code other} is not {@code null}
	 * @param other
	 * @return the strongest type weaker than this and the given type
	 */
	public RefType join(RefType other);

	/**
	 * Returns the type of a field with this type when accessed through the given permission
	 * @param p
	 * @return the type of a field with this type when accessed through the given permission
	 */
	public RefType leak(PermKind p);

	/**
	 * Returns permissions for array dimensions
	 * @return permissions for array dimensions, never {@code null} but may be empty
	 */
	public PermKind[] getElemDims();
}